Respirators of the type indicated above are housed in stand-by containers which can be closed airtight and are used, for example, by miners who carry them constantly on their bodies. The device is removed from the stand-by container for use in an emergency. It is obvious that, in terms of weight and size, a respirator of this type must be light and small if it is to be carried about continuously by a miner.
In a known respirator of the general type involved here, the respirator bag is located above the chemical cartridge, and the chemical cartridge is placed int he lower part of the housing; the respirator bag with its breathing hose and mouthpiece are located in the housing cover. In this way, a relatively tall housing cover is required, which therefore plays an important role in determining the overall height of the stand-by container, and as a result the respirator, together with its stand-by container must be worn on the body by means of a shoulder strap. Under the extremely harsh conditions which prevail in mines, this method of carrying the device is burdensome to the miner who must carry the device constantly.
In other patents, such as East German Patent 60930 to Schwanike, there is an attempt to reduce the tallness of the housing by placing a cartridge inside a respirator bag. Thermo-insulting material in the form of protective shields is placed between the respirator bag and the side of the cartridge that rests against the bad to protect the oxygen-filled respirator bag from the intense heat produced by the cartridge during operation. The cartridge is connected for gas flow through an exit portion to the respirator bag and to a valve cage at an entrance portion. The respirator bag is also connected to the valve cage at a different location than the cartridge. Besides the bulkiness of this design, two additional problems exist. The front of the cartridge is exposed to impacts, such as bumps, during the user's work which can compromise the integrity of the cartridge. Also, the structure with its insulating protective shields is heavy to carry over extended periods of time.
The present invention is therefore based on the task of creating an especially lightweight, durable and compact design for an oxygen self-rescuer used as an escape device, and to design it to be so lightweight, durable and compact that the device can be housed in a stand-by container to be worn comfortably on the belt of the person carrying the device during the rigors of the mining work day.